Improvement of okara mouthfeel by Aspergillus niger and Aspergillus oryzae fermentation

Okara is the byproduct of soy product with rich protein, dietary fiber, mineral, but it is not welcomed as edible soy product mainly because of its poor mouthfeel. In this research, Aspergillus oryzae and Aspergillus niger were used to ferment okasa in order to reduce the particle size distribution and improve the mouthfeel of fermented okara. The results showed that both strains improved the mouthfeel of okara through fermention at 28℃, relative humidity 95%. After fermention with Aspergillus oryzae and Aspergillus niger, the particle size of okara decreased. The morphological analysis also showed the reduced particle size of fermented okara. Furthermore, the cellulase and hemicellulase activity were detected in the okara fermented by Aspergillus oryzae and Aspergillus niger for 3 and 10 days, which suggested that the both strains could induce the generation of celluase and hemicelluase in okara and lead to reduced particle size of fermented okara. The research can provide a new method for the unilization of fresh okara.